Hydrodynamic fluid divider for fluid measuring devices

Abstract

A hydrodynamic fluid divider is provided whereby by a shunt line directs a portion of the overall flow of a defined fluid stream through a flow measuring device, such as a Coriolis mass flow meter. The proportion of the shunt line flow portion is determined by the relationship of various fluid restrictions within the shunt line and the main line of the divider. The measured flow value for the shunt line flow is utilized along with a scale-up factor to determine the overall flow through the divider. The proportional relationship of the shunt line to the overall flow permits a reduction in the size and operational requirements for the flow measuring device.

We claim: 
     
       1. A hydrodynamic fluid divider comprising: an inlet for receiving fluid flow;   an outlet for exhausting fluid flow;   a main line for directing fluid flow from the inlet to the outlet;   a shunt line for withdrawing a portion of the flow from the inlet and directing the flow portion to the outlet separately from the flow in the main line;   a balancing plate positioned in the main line having at least one opening therein for passage of at least a portion of the fluid flow from the inlet, through the main line, and into the outlet;   means for measuring flow characteristics within the shunt line;   a first restriction plate positioned downstream of the balancing plate within the main line; and   a second restriction plate positioned downstream of the flow measuring means within the shunt line,   the first restriction plate having at least one opening therein, and the second restriction plate also having at least one opening therein, the open area of the second restriction plate opening with respect to the total area of first restriction plate opening and the second restriction plate opening being proportional to the portion of the overall fluid flow directed through the shunt line and the flow measuring means and the balancing plate form equivalent restrictions on the fluid flow through the shunt line and the main line, respectively.   
     
     
       2. A hydrodynamic fluid divider as claimed in claim 1, wherein the balancing plate is formed as an orifice plate. 
     
     
       3. A hydrodynamic fluid divider as claimed in claim 2, wherein the balancing plate is formed as a cylindrical orifice plate. 
     
     
       4. A hydrodynamic fluid divider as claimed in claim 1, wherein the first and second restriction plates are formed as nozzle plates. 
     
     
       5. A hydrodynamic fluid divider as claimed in claim 1, wherein the first restriction plate is formed as a cylindrical nozzle. 
     
     
       6. A hydrodynamic fluid divider as claimed in claim 1, wherein the inlet to the shunt line is positioned upstream of the balancing plate. 
     
     
       7. A hydrodynamic fluid divider as claimed in claim 1, wherein the inlet is formed by a manifold which splits the input fluid flow between the main line and the shunt line, and the outlet is in the form of a manifold which receives the fluid flow from the main line and the shunt line and outputs the combined fluid flow. 
     
     
       8. A hydrodynamic fluid divider as claimed in claim 7, wherein the first nozzle plate is positioned within the main line upstream of the discharge manifold and the second nozzle plate ia positioned within the shunt line upstream of the discharge manifold. 
     
     
       9. A hydrodynamic fluid divider as claimed in claim 1, wherein the second nozzle plate is positioned downstream from the flow measuring means. 
     
     
       10. A hydrodynamic fluid divider as claimed in claim 1 wherein the first and second restriction plates are formed as cylindrical nozzles. 
     
     
       11. A hydrodynamic fluid divider as claimed in claim 1 through 9 wherein the flow measuring means comprises a Coriolis mass flow meter. 
     
     
       12. A hydrodynamic fluid divider comprising: an inlet manifold for receiving fluid flow;   an outlet manifold for exhausting fluid flow from the divider;   a main line for directing fluid flow from the inlet manifold to the outlet manifold;   a shunt line for directing a portion of the fluid flow independent of the main line;   means for measuring flow characteristics within the shunt line;   first restriction means positioned within the main line;   second restriction means positioned within the shunt line downstream of the flow measuring means,   the first restriction means having more than one opening therein, the second restriction means having at least one opening therein, the open area of the opening in the second restriction means being equal to the area of each opening in the first restriction means and the ratio of the number of second restriction means openings to the total number of openings in the first restriction means and the second restriction means defining the portion of the flow directed through the shunt line.   
     
     
       13. A hydrodynamic fluid divider as claimed in claim 12, further comprising balancing means within the main line, the balancing means for forming an equivalent flow restriction within the main line as created by the restriction of the flow measuring means within the shunt line. 
     
     
       14. A hydrodynamic fluid divider as claimed in claim 13, wherein the balancing means comprises an orifice plate having at least one opening therein. 
     
     
       15. A hydrodynamic fluid divider as claimed in claim 14, wherein the orifice plate comprises a cylindrical plate. 
     
     
       16. A hydrodynamic fluid divider as claimed in claim 12, wherein the flow measuring means comprises a Coriolis mass flow meter for measuring the mass flow rate of the fluid flow directed through the shunt line and means for calculating the total mass flow rate through the divider in conjunction with a scale-up factor defined at least in part by the open area of the openings within the first restriction means and the second restriction means. 
     
     
       17. A hydrodynamic fluid divider comprising: an inlet manifold for receiving a fluid flow and dividing the fluid flow into two separate portions;   an outlet manifold for receiving two flow portions, combining the flow portions, and exhausting the flow into a define fluid stream;   a first and second main line portion each receiving one flow portion from the inlet manifold and directing the received flow portion into the outlet manifold;   a shunt line communicating at opposite ends with the first and second main line portions, the shunt line withdrawing a portion of the flow from the first main line portion and directing the withdrawn flow portion to the second main line portion;   a first balancing plate positioned within the first main line portion upstream of the inlet to the shunt line;   a second balancing plate positioned in the second main line downstream of the outlet of the shunt line, the restriction of the flow by the first balancing plate and the second balancing plate being substantially equal;   means for measuring the characteristics of the withdrawn flow portion within the shunt line;   a first restriction plate having at least one nozzle opening therein and positioned upstream of the outlet of the shunt line into the second main line;   a second restriction plate positioned within the first main line downstream of the first balancing plate and downstream of the inlet to the shunt line,   a hydrodynamic balance being created by the first and second restriction plates so as to direct a fixed portion of the overall flow through the shunt line; and   means for calculating the characteristics of the overall flow through the divider as a function of the portion of the flow through the shunt line as determined by the measuring means.   
     
     
       18. A hydrodynamic fluid divider as claimed in claim 17, wherein the first or second balancing plates are formed as orifice plates. 
     
     
       19. A hydrodynamic fluid divider as claimed in claim 17, wherein the measuring means within the shunt line comprises a Coriolis mass flow meter. 
     
     
       20. A hydrodynamic fluid divider as claimed in claim 17, wherein the first and second restriction means are formed as nozzle plates.